Applying epigenetics to the real world

We all know that how our bodies are treated – by both ourselves and by others – can influence our health. Smoking increases the chance of developing lung cancer. Obesity increases the chance of developing type 2 diabetes. Living in areas with a high level of air pollution increases the chance of developing asthma. Many people ignore these risks, but what if they knew unhealthy habits might impact their children’s, and even grandchildren’s, health?

Epigenetics

(n.) the study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself.

Genes can be expressed or not, or turned “on” or “off.” Epigenetics isn’t about changing the gene itself, it’s about whether that gene is being expressed. That’s not new information. What is new, however, is that recent studies suggest that it’s nurture, not nature, that influences the expression of genes.

Factors such as smoking, eating a ketogenic diet or exposure to air pollution all have an epigenetic influence, and those influences can have lifelong effects. This all may sound

Dr. Pat Gabbe

obvious, but the field of epigenetics is relatively new, and researchers are still learning the implications. Epigenetics has a vast range of implications, but for Drs. Steven and Pat Gabbe of The Ohio State University Wexner Medical Center, learning how epigenetics can affect pregnancy and preterm birth is paramount.

“The impact of the environment on the DNA and RNA has a long-lasting impact on the mom, but it’s an intergenerational impact,” says Pat. “It can actually be passed on by genetic codes from generation to generation, so it’s a powerful stimulus that’s relatively new. We didn’t talk about epigenetics before, I would say, the last decade.”

Pat, founder of Moms2B, an organization that provides support to new and expectant mothers in high-risk Columbus neighborhoods, has seen firsthand how not just factors such as smoking influence the gestational period and health of the baby, but also how unstable housing, sleep quality and even the degree to which the body reacts to these situations impacts the success of the pregnancy. And these factors boil down to one word: stressors.

When expectant mothers are exposed to higher levels of stressors for many generations, research suggests members of that family may not only respond differently to stress, their biology actually changes. Their bodies have a greater vulnerability with increased inflammatory responses – biological responses – to stress.

“People always assumed that you were born with your genes, and that your genes determine how your body would function,” says Steven. “Now we know that because of environmental factors – stressors – methylation of the DNA alters the way the DNA is expressed.”

In other words, the DNA for these negative alterations existed in your body the whole time; they just needed an external influence in order to be expressed. This isn’t science fiction. Pieces of our DNA, or telomeres, are showing researchers that epigenetics is happening in our bodies every day.

Telomere

(n.) a compound structure at the end of a chromosome.

Picture the plastic tip on the end of a shoelace. As this plastic tip shortens, the shoelace becomes tattered and unstable. Though not a perfect metaphor, something similar happens when the telomeres, which cap the ends of our DNA, shorten.

Stressors cause chromosomes to duplicate more rapidly, shortening the telomere, damaging the DNA. Shorter telomeres are linked to a higher biological age, which is linked to increased ailments and chance of developing diseases such as cardiovascular disease, type 2 diabetes and hypertension. For pregnant women, like chronological age, biological age is hugely

Dr. Lisa Christian

important to the success of the baby.

“We know chronological age has an impact on birth outcome,” says Dr. Lisa Christian, health psychologist and principal investigator of the Stress and Health in Pregnancy Research Program at the Wexner Medical Center. “We’re interested in looking at how life stress and other related factors such as sleep quality and depression can affect a woman’s biological aging and their birth outcome.”

Christian’s program is examining four factors that may contribute to telomere shortening: depressive symptoms, racial disparities, maternal obesity and nutrition, and maternal sleep quality. The program will monitor outcomes including cardiovascular function, immune responses to stress and the inflammatory processes. Christian and her coworkers aren’t uniquely interested in these influences and their impact on telomere length, however – the Gabbes have been paying close attention as well.

“The telomere length reflects the environmental stresses and epigenetic phenomena,” says Pat. “One of the first studies done (on telomere length) … found an association with maternal stress and the shortening of the telomeres of their newborn babies.”

Disparity

(n.) lack of similarity or equality; inequality; difference

Because it’s not known what exactly triggers birth – no, foot massages and spicy foods aren’t really going to induce labor – researchers and physicians are combining all of the research they can to combat preterm birth, and that means pairing telomere research and epigenetics to get as full a picture as possible.

Dr. Steven Gabbe

For Christian, that big picture is important, but looking at individuals as individuals is the goal. Did the mother grow up in a low socioeconomic situation? Did she receive improper social support growing up? Both increase the probability of the mother having shortened telomeres, but one focal point, for Christian, is the social disparity between white and black mothers – not biological disparity.

“Our data suggest that African-American women have greater vulnerability to biological dysregulation when they are exposed to psychological stress or poor sleep, including differences in their inflammatory responses,” says Christian. “This is a line of research that my lab has been pursuing for quite a while. When you have a group of people who may have had multiple generations of exposure to stressors such as lower socioeconomic status or systematic racial discrimination, that can certainly have an impact on health.”

Researchers have observed black women are more likely than white women to be exposed to those four stressors being examined by Christian’s study. As expected, Christian and the Gabbes are also seeing black mothers with shorter gestational periods and shorter telomere lengths than white mothers.

“There hasn’t been a great deal of progress in terms of addressing racial disparity in preterm birth. There is a lot of evidence that psychological and psychosocial aspects play a role in these disparities,” says Christian. “Our lab is aiming to look at how stress can get under the skin and affect biology.”

Though preterm birth is just one of the areas in which epigenetics and telomere length can be applied in the real world, researchers and physicians are working here in central Ohio to learn more in a lab setting, then apply findings to help real people.

“(Epigenetics) is changing how your DNA expresses itself. That’s what the whole field is about,” says Steven. “We know that the way genes work now is not simply that they’re going to work the way they’re going to work. There are factors that occur during your life that may influence the way your genes express themselves.”

Amanda DePerro is an editor. Feedback welcome at adeperro@cityscenemediagroup.com.